Fine-tuning Flowering Time via Genome Editing of Upstream Open Reading Frames of Heading Date 2 in Rice

Abstract Flowering time of rice ( Oryza sativa L. ) is among the most important agronomic traits for region adaptation and grain yield. In process breeding, efficient slightly modulating flowering an elite cultivar would be more popular with breeder. Hence, we are interested in increasing expression repressors by CRISPR/Cas9 genome editing system. It was predicated there were three uORFs 5’ leader sequence Hd2 . this study, through uORFs, got four homozygous mutant lines. Phenotypic analysis showed that hd2 urf edited lines flowered later 4.6–11.2 days relative to wild type SJ2. Supporting phenotype, Ehd1 , Hd3a RFT1 significantly decreased than type. Moreover, found transcription level not affected, whereas protein increased compared type, which indicated indeed affect translation a downstream pORF. summary, developed approach delaying heading date based on uORF repressor, labor saving traditional breeding. future, other related genes, including promoter repressor can also used as targets fine-tune varieties.